Anne gazed dazedly at the Inspector. “I don’t understand,” she faltered. “You found the knife—”
“In the wrong place to establish your theory—of suicide.” Mitchell’s covert smile was ominous, and Anne shivered involuntarily.
“One moment.” Curtis changed his cane from one hand to the other, and stepped closer to the Inspector. “Mitchell, suppose you have the sergeant drop a penknife or ordinary knife through the banisters.”
Mitchell looked at him keenly. “You mean—?”
“To reenact the scene of Sunday night, or rather Monday morning,” replied Curtis. “Tell the sergeant to stagger and fall. As he does so we will see if the knife flies out of his hand, and through the banisters, and thus know,” his voice deepened, “exactly where it falls.”
“A capital idea!” declared McLane. “Go to it, Mitchell. I’ll stay here and you watch the proceedings from above. Wait, though,” as Mitchell started for the staircase. “To make the test as complete as possible I’ll give you a scalpel from my surgical bag. It’s here with my hat. First, however, take this,” and he handed the handkerchief and the discolored scalpel, which Mitchell had found concealed among the ferns, back to the Inspector.
As McLane took another scalpel from his surgical kit, Gerald Armstrong ran down the staircase and joined Anne. He was followed more leisurely by Lucille Hull. She shuddered slightly as Mitchell displayed the discolored scalpel before wrapping it securely in his handkerchief and placing it in his pocket. To Anne the minutes seemed endless as she waited for Mitchell to mount the staircase and instruct Detective Sergeant Brown in the role he was to assume.
“What is going on?” demanded Armstrong. He made no attempt to modify his naturally strident voice and it grated on Anne. McLane caught her sudden start, and guessing the strain she was under, explained the situation in a few words. Lucille listened with close attention, her eyes following the movements of the two men on the floor above as far as she could see them.
“Watch out, down below,” called Mitchell. “Stand back a little further, Doctor Curtis; you are too near.”
Curtis retreated a few steps. Anne put out her hand to guide him but dropped it hurriedly on catching her cousin’s gaze; there was a mocking gleam in Lucille’s eyes which brought the hot color to Anne’s pale cheeks with a rush. It had not faded when the silence was broken by the sound of a heavy fall.